SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fe59ea46eb8c7f4a9677c4e04ff5ad287a80974813f251c88d9f198d2bfdab7' 
  AND token = 'KJNwFtelpRFB+8sE8+jU6BVbSBZ5HLiOgQchHaIOs9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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