SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a63c9c0546c2381b0c44be6648961f353f612b5d3731e1edaf79c1fa0fd98b8f' 
  AND token = 'hurJdbZoOAXkYBijqqiE01r3aKsqwEFvt0Hyzx77A7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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