SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33a0ce5b738e46891558d4a46ce95dd21693edd8619594b7d31c12cd8f813fec' 
  AND token = 'k9c1pGnjsPG1fkRDp7zunOlmIAjbfcWaBND2ONxF8dw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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