SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7dd22ffdca74ca77abf75bcb7da65a760eade4be895bd0efd5f2be9ec81eb51' 
  AND token = '9cZWKgQmPAhdWqlsVg90FsfJnS6z2iraeLw6+WiJJYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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