SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e63fc7936bcd959d1871752d4ba28e6fdc63a614be2be1915e8d130678956f60' 
  AND token = 'ZmAyEIwg7AEFpXug2bqDGoTu9LB2ytK8Mmleaiw3Nnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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