SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dd56d5f957bda5445a2495a4b88603dcdf2766d4dfbb54a6731e0c5eb69a7a0' 
  AND token = 'jzth6CUM4jQQT/2xm8ggP7Zg4SgyqRRniBpe+bV3z/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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