SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bf26c9cc246e444b47743c5caf5d29e5cd109539a2c7ec1096f583e061bfddc' 
  AND token = 'XcBUK2iWpi/JbPOeh3+c1Rd/2UEgvASRo91/wbCARt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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