SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5daaa53b405c346f2db2cc1da7aa4740d01b4ac52336cf0c491aae3f12280032' 
  AND token = 'NqaWmsuYEKnGyciYMfkLREHMLzG7XDMJuWy1kh0tt8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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