SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b86ac6e8761f1d1f2407d88d7008eebb485f74d6d0749289ca52767d7309333' 
  AND token = 'DSVYkZUSvmWOGJbjlU49MY9IHf11AmR5qGplwzXH2pY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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