SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ad5ec73ebbc26d1903171e2553a9d021ec92a67f527681fcb5453386003da71' 
  AND token = 'H3JEwFXYRP7thkGZOSnoTFTd9DE9Q8c1tCtiiUywtuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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