SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f81404fb13ec08fda82ffaa4be89d80dab3d980212f5c3ac602441a82ed472aa' 
  AND token = 'Avrio/Uqr+cyLEObYCYbQ0laSmdL4Ew/3qXmt9dkS+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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