SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85dd91c5279addb53431907670f3def0e6c18326dbf3efd9d40b398fa34dc61f' 
  AND token = 'lSUPWp6RrSj63mdiHlvqTWhcKZssFvVZJRvU1xGAxdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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