SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d2fb3ad888e94b2c191360b72d41fe36b8f8165470e37d1f0e123852e947b9e' 
  AND token = 'Gg5Cw9E2VYbLGyT6V0QK5IJSFVYAHl4TVXmNjyA+Vrk=' 
  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"
    }
  }
}