SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4c52629a059ccd2d32b6cf26332777694c806b5b3ced63aad313f8c8df0649e' 
  AND token = 'XsYegmEElbx404DluV43ihnmWL60Fozryq1NTOUNlLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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