SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48b124e8b9be571873810e88f3e8d52438a09691edfd19268226dde367c13ffd' 
  AND token = 'cGT5Ulws2uXB3+T6YpnqNXoy9AlKEJetB59u4VpwF50=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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