SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e257851ba527d44314c5b61c20d906dfa5e3195812c9e90732b32322a723072' 
  AND token = 'DGzKyy5xGU5uHxGVyfkdKB3YZDKoGRG6aoArhSRrm10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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