SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a286d040b2db0aadd9c61015ae5b5bedb0bff334d73c2736e7159a47df7b279' 
  AND token = 'e3VbGJo+QuX5Xs/gKTuejIsm4anE/PTix0aCpp+zaLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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