SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ff1698e695f12521e3f098d4b0e7e232b1c627a935ef1b0feb73f57dd4e8da10' 
  AND token = 'K5Gj4y9uYxOq6miy5wMmv/LIONOIv82jHTh0sWujphU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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