SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8619a56a93b653dd213cdab96609ff000836c2ab41fcef470fbd87f0b28318d5' 
  AND token = 'oEX5Xlm3ZYchkv1Eq05WpcSu4cHOXASfpEpunoqhmAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00062

JSON explain

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