SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5cef90d4981aedbbd085ea0346086a44946294f2e46a2bea8994c2eac7f7bd2' 
  AND token = 'SjZyXjGBQy2V2ctZnaSbTLG+Mi5hwC41WnGI4AaTgO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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