SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '555660346dbc3557a47bf92d521a57fdc26f00014cc745f0f975a802ccdb2cdb' 
  AND token = 'AZnEpDdqzClylneyJKXTmr9Ex7Odf/M8pjxgq8I0o9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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