SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9428db1befff7970f3a784d4e6b3c18477c4297068be027cc2094424a9114c45' 
  AND token = 'dQnCis24j+/ypTEkA00GHt50gCdNMXjIHPoN++hrQq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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