SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe0fc27605c6ea4be829faafeb66cdcc41bdee95a3e0d3f3925fc6bc6a29f07b' 
  AND token = 'RWfczUUESiHIry4ETBXFwja0XN6BnE0Sd9/9SZbOI1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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