SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5405ad5db847cb10373cc9967911f83acbe0405e8ea8515e5747821ab18a098e' 
  AND token = 'jGoYDms+jTRFFsq6zEAU7at7pMMqHf9mV6JlgNP3mNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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