SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '371b7da4b8e0629ae91889512c79166e8a819f5cb01c5c69907c9d57de9a121e' 
  AND token = '4XnfdwjRVjZY9NglpVG2JKQF0k+yyXFvfhWyecJdt/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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