SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55b3c6d36b22c41ce1757e50aa834f59c28cb33d99363cb5ac72089962f13f89' 
  AND token = 'yGpGjhaLeR0518XFWqRkfp+gYHZgqlJ6sjEipdkAV/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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