SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8f07b8fb5e04620cb1231f4a7c3ffdfebdd0a45008483dc626589f0ba56a10d1' 
  AND token = 'bJQYVr2xuffM2BsxqweXlIan9+qaQDDtSkKne9MNzxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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