SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5647205f868e22cfffb68254c81725faca0cfdc25570ea55179bc4cf5441c156' 
  AND token = 'eiAb4qnha7RmcWjfeDAh9zp/8O5ciSE2b/yYnsyNLDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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