SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7fae86b64c83735a0aeac99d5aa8a5510bb1eecac38a4dc72f67be1fd5f2330' 
  AND token = 'NAFBZ17Mzww34ctPKbnH8s9Z9CiIfZ1JBb2LaQvEbEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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