SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e77eec773e641ee9c75981688ed21fde896b5a38d23fff3f984e6b703b07c6c7' 
  AND token = 'ZA1aIA+sNsB/pV8+3vVJZJGc6BVzUqBO2oPPuMhjf3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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