SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9a0b8f34a9c2e9480ad9c0e33b7d410e2f7471022d34c5f117c5e11a1fac746b' 
  AND token = '57g0v25/7QfqmaZWmq/nk+kIJnqph0atvHOESYPg9RA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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