SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1791163b91446d675074b2784a2d84b4d538fe40bfc5ea49b5f94b37580d7d83' 
  AND token = 'MgepaGEOMSGZ2LCl/fadzx7jT+BTiMrY8g+/BFg5fDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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