SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b15e080a09aec99e48b9ff8778d63cf97340020948cf51608db3fb1832cc8e22' 
  AND token = 'Iia6anHZq+CAlnk9EZXVlJ4Kcbl+xEtVi5ZyYwklsKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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