SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f244ea5639c38268228647a9e16c26ab07edfdd2e207252a6763df10a1c56216' 
  AND token = 'eJ+dyXmf74doZXFm1qnQhtPqUe/q29BF66OGABR9Ubs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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