SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97934c05714c39d4036add0126c71df487aabeebbce43508649cb6ce3246a81e' 
  AND token = 'lAlRg0+GmiLQuoJmOdrub4SavJ2bdb8gS8W1sUuMHs4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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