SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faac88472642a19fcef029f594ef53b34c636c13830de55796af14255fec06fc' 
  AND token = 'sr4taDT3ioAj9vvC+h3vrK3qQ0XehveMJOZ3DEnm2So=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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