SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a08bf48e10f9703cb9dbd5b90724572be53b9f670841d6d9d98b627ba510a8c1' 
  AND token = 'vvOkzAlH/KOB2SnHrzxgJ1R/2RDo+9Kk5R7MHOgIGC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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