SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11115c72a0a3dd6d6a6891af7778add4109252091244e7496571dee93cd03cfc' 
  AND token = 'WWBJIsNZlJrsPwoZZ3rK9ilfLWDMgvGDB+EOSNxptyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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