SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7be619e50b667a4bffb23d805c34afea4662effe03ccc0d8ac88ebbfb91c9640' 
  AND token = '7laGpDgtdTFNMCNHOuEuaYA5R9yhQ/spmpMtyR4zZLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}