SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cea20f861143076650930a5a2a27d70aa72ac4f73e1256cc248089fd3c1034e' 
  AND token = 'NUxkTtKQl3BmzFNkSbegtfaGOhUf53gZEyOH7Jx1SF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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