SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7354918a369cef47583f40ade6b97c5deb2f14b4943bfd3be390bf80e0bc1681' 
  AND token = 'KubI0MD9RVyYVC8EyeyZmbnOC5sObR08XpXJQ5/L2t8=' 
  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"
    }
  }
}