SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d788cb783519fa15568e0b3038720c452b7487d164ccb9daf9ef0238cfb3666' 
  AND token = 'ukzqR0wu9JoXcR3aWq6D5wXgQWs0/y4FHhDxcc3etYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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