SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b94bb934a771df249ff78bc36cea51dd4c506d5d93d068253cdec3e452720ff' 
  AND token = 'R7eURHl7EniVR9Z3NLy46uwYkjVC7RsK5iHkFHE/sHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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