SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '68b5d061fc70fad0485d4ad08da083bddccdd7762b1ace1d3c093fbd0ff8ef13' 
  AND token = '0Gc4PvwcBJp5mXAJvuy++mQHb8I6WzDjEGq2hN91R3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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