SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f40b891f06f73054e20e12e70db322605e00d8706b9bab7827dcd9ecca82266' 
  AND token = 'D0wgfRpN/VEz5wrszV2cDKTDsUjHVYxnZayi6qXdPEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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