SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f6f2b577bd9ac47a98cdc81e03cd41be99ba3dddd3971f111e0c0a881b28f2fb' 
  AND token = 'vFoeKIdafc1Y8NxY2TESmA4ysNnYQfqIMgssGkhkQoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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