SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e26feca8878f9962689d33673faf0bdfded28948a52e0b7a0fdc457d1025b114' 
  AND token = 'Y4KuEfbxJG0Q/BHsiAoj0uhVASdNVW0+3Vj5lyR16LY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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