SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6447e407796724978e097bd58b81166576aa1ee77e1cdc5329a19b942fd65cd' 
  AND token = 'BOq1FIHpdcrsuizdCjogIK7jaJ/RCgysjm4B8wkhjfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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