SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8041f5ece5f041107f271663b50474128243fd9af0ab4e36dbaa18cd8f4546cc' 
  AND token = 'iIMivo4w92gIFIBa277fYWJCdzqxioUYWpPo83B8+LE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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