SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dcc361d8e98f5b5414612e7f0e0bf5962c84b2549b3327f6779fcc835fb5dd1' 
  AND token = '3Q+a5BzDBgLm7Glf8viOuPlkI55rYRUZEloZ/cNaD+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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