SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc31ece05f79026ce5d6e6d6cd859f37f4b3953d59e3bf7d8dec0c2d312251ea' 
  AND token = '7eoFUNIwcX3T7NtPLspbsYYtVesTBY5j6EovojEwYhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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