SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0aca90c416cd06bf37c257aed7651ad686f82a117707e78729d55f24707cf32' 
  AND token = 'OnSsY/My6oPK8t+W3qkBBUgd8cGCv9xTaOaAVg0s/iY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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