SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7716fb50eb5aa39bf1a153365b29ce7852df70b94881bc94d75d5c2290298d15' 
  AND token = 'Me1lCY/FPl6VUOv+DhaJylFbThragQAX92A5MCBh0uw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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