SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20e6ebdcbad86eecb993b5131af4c490b71a420ac7d96d8b0e3f741b73632f93' 
  AND token = 'ntUOFXIA4y4vM+VCYw9Lm+GPOwHbr2aFhIvPDNBVxhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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