SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55164f0e1af95c30aa9899f5e80c3c73ec149b2b60457a4d416f33cf80d87daf' 
  AND token = 'ZuMG4TydUX0yJaOAbYKT+btBt61OUS7qp5e060DH7Ok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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