SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65ad517a8ed669341ffded6e2c8819135a9e05637197de465359fdce4fbf05ea' 
  AND token = 'x5Yzq/fP4LRLV+20j2omapmWhvJBNbZ0WcKNG/hFwjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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