SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37f41e46d53d0c23d2d15370a2111ca2edace597dc8b0aecb0cf7eebc7eaf6fb' 
  AND token = 'rUhH7vAUXrPDGnghwzdKWyobQD0aCrrH+k6FW7sS/jc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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