SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a579cd68462fb0104a993ee101aea051bdd33db41ea1972045a72b3f3ceb318' 
  AND token = 'GxyPugweyjJMh4A6IXvqveqZJMlLMR0EU7VMep8zk2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}