SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b700243a49f0f8840d2c355a3fa3166861d2eb6824343dadf86587979af2990' 
  AND token = 'YAwELa05951H/Ocyk4vO3AKv9KIQXolx3ofN09ksZQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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