SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f58e6f979d2eefa3a5808942b8efbb9bca1d357c768d5bc57e2cce4395ce4ca0' 
  AND token = 'EZCoyZJEkmOgKxnlJhfP5zl9xsCUFuitgqa9mRapWV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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