SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c632d274eab3eb0b8d271f56236c310ba027180748cf63a20994a589faf3d4c' 
  AND token = 'oYgKpsJaUzOeTD0zTucVkAzsIowmKbtyTqkYicM7vaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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