SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cd7e7db80f088648eac6739e0ab16f676c7a019430829da9c41b64aa964feb1' 
  AND token = 'roy+8WeBh33gHpXhzT6BLWUE3fb7Nm/rWXpwUgsWfl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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