SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd55dacace1f6c4bd2b35e077766c5eddaacb7db6c4097263ea77f56c9eef0330' 
  AND token = 'zVej/Hd8jkgSxBllVpU6vnINFAdzi1G0eux4n96/okc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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