SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7e871e88060e66f7797c3b7770c80cb504d87efd8d048807309e19963f5ea82' 
  AND token = 'dTBpz8ikuIOp7ejSTOndCC0bKrkkQm98qkox1ct5ZPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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