SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e06f0f767773c8e2d4c3b0396a68218e610a0d0b709ee0d9d5b8080ad545b38' 
  AND token = 'K5c+rFxE3IpRqx706+JcuFoZvHfZLJgOKYWoKUjENec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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