SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '283218bf1306a247787c677ff13a60fe5175dbda7ec18b9d5f21e19e0ab9bd1a' 
  AND token = 'kq+CovBd9XH4NKZ7nscyYPnwNXy/aNvdpj92FjzWjNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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