SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2016089dd751d865fbd0217744c454dacf67e79e029117ab866f4fe87571d0b3' 
  AND token = 'VBHQ6QJq/0VY/Y9JtrKw6usR4Phu0Z/DEFTSxXGyxPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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