SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'babcfe4d6a8cb3931134405409adcb264dc620a3a1ed4bb1604077235efcb3a6' 
  AND token = '1zg4jVoKBF9AhwyQq6yqRN/YKEPnG9BaQl0dIhrf+SA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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