SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85747282460e290e8b1d4f1a43c2d516431fa023bfb9bf51c6f125c6f6a234b2' 
  AND token = '8gWng/CF9Y7yyJ4Lw/RPi6NLlJ9rdyVlLXPcZ3VfIvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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