SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2af1be2f0f3c5af507d3a4f757108400996cb6ec4ec3a127fcbc3d94d763040d' 
  AND token = 'nKpXplikndzTmGMGmYWVQYzKdaW962tlISsBpPLSVrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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