SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '565dafd09813876021154ca528da13294491c85d52b2d80a8b1adbc9cef129d3' 
  AND token = 'BHU+Lp4r2KxvzWaZSmJwYGe5QN4AoS6Fh3YU6Y0aMPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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