SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cd3696cf251f3fbc511b6039df61e5ca021c1c3b98b7da8946bbe7be3dca7997' 
  AND token = 'uf8ToX8W+OFEaRdefvF0k7NmUPaxIPpZ5CRoj/O58go=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}