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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2a31d71ac4e27ee6bf3ce8ffa1294ee84c968a577dbacef6a703ade11e88aea' 
  AND token = '6Xcm+4vsKpIYBVakRIy88R0x8o2xhZ/VZDRSggkxlBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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