SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82361c213e70728ffc856823f80648eb6bb23b1ec25d4a279d4e97f155ed3dff' 
  AND token = 'c0DWbrwG7XXFw1+M8l8TeaVqg5wRQkz4xSuKQKCI9/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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