SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d03c44a6213c8d953c622a8b0d4813583cbe0583a459b0ddeefea6c277b326e' 
  AND token = 'ml3a95ZEPyuNFLa9YtzW/JbrXvoZOQlmmWTtGHLGqnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}